1969 1/2-1981 Pontiac Buick and Olds coolant sleeve seal inserts

A pair of coolant sleeve seal inserts for 1969 1/2 to 1981. Corresponds with Gm part number 9796347.  These bridge the gap between the divider plate and the timing cover and ensure that the freshly pumped coolant actually flows through the block rather than around in circles inside the water pump cavity of the timing cover.

What's the coolant path ?

The water pump circulates coolant from the radiator into the block by pumping coolant through the water pump sleeve/seal assemblies. The coolant moves through the block and up through the heads and back to the thermostat housing. If the thermostat is open, the coolant returns to the radiator and back into the pump through the center hole of the divider plate

Reducing the gap between the backing plate and the impeller

Pontiac owners have reported that (1) heat cycling may result in a distortion the backing plate and (2) coolant degradation may corrode the backing plate necessitating replacement.  Some aftermarket plates may have a deeper dome and incremental cooling gains may be experienced by reducing the backing plate-to-impeller vane clearance. In closing the impeller-to-plate gap pressure is built, efficiency is achieved and more coolant will route to the thermostat and radiator which initiates the engine cooling process.  Please note that inadequate clearance that results in an impeller vane to backing plate interference will cause friction.  Owner modifications to the Pontiac part design are performed at the owner's discretion and FAILURE TO MAINTAIN ADEQUATE CLEARANCE WILL VOID WARRANTY.